Don’t recall where I found this, but FWIW:
“Wood Framing” - by Trevor Bolt Yacht Design Ltd.
Use real white bending oak from the South Eastern U.S. The lumber
of course is green, kept in the shade, stored wet and salted down. Framing is even tougher work than planking. Better to work when its cool. It is a good idea to relieve the planking of the caulking before reframing so the planking can move when fastened and have good tight contact with the new frames. Prepare the boat by clearing a path for the new sister ribs by removing blocks and nails etc. Cut notches for the new frames through the engine
stringers and notch sockets into the keel
Steambox time: 1/2 hour minimum for small frames, an hour is fine for most. Do not oversteam, it ruins the strength of the wood. Put only enough frames in the steam box that you will be able to put in the boat in an hour period. . Again shores and wood wedges are indispensible. A handy item would be to have a metal cap you could put over the frame head
to prevent them splitting as you drive down the frame between the planking and the stringers. The frame corners should be bevelled to prevent splitting in this case. Bevel off the bottom outboard
end so it will not dig into the planking as it slides beneath the stringers or around the curve of the bilge
, heading under the new notches you cut in the engine
stringers until it sets into the new notches cut into the hog or keelson. During its journey towards the keel
it must be shored and wedged into the curved shape of the bilge
radius or it will simply knock off the planking. The planking may have to be shored up from the outside to prevent this happening.
Once pounded down solid into the sockets and shored and wedged out against the hull
planking it is time to nail. One person on the inside with the pinball backing against the frame close by where the nail is coming through. This stops the frame from bouncing and ensures when countersunk that the plank and frame are well cinched tight together. The nailer on the outside can nail in a series so not to confuse the inside assistant. After setting the nails with a nail set, the small amount of boatnail that protrudes through the frame inside may be banged over flush with the frame face. The boatnails are chisel point. The chisel point cutts across the frame grain cutting it, instead of wedging and splitting it. You will notice the nail heads are elongated to provide more grip across the plank grain rings. One frame may take 5-10 minutes, so if you are putting in 8 at one time into the steam box you should be OK. A steambox can be made of plywood
with 2x2 in the corners. Sections 8 ft. long can be made to join together. One end must have a hinged door. A metal pipe goes to the boiler. I always have used two steel
drums. A 25 gallon 'boiler' suspended inside a 45 gal drum burner. I use a 20 lb. propane
tank and tiger torch, it will last for two hours wide open. Wood works fine too but may damage the ground from all the heat. When opening the steambox door expect a blast of steam to go up your sleeve, so wear gloves. After reframing, the boat must be recaulked.
OK, I found the reference - Goto:
"Planking & Framing Wood Boats"
You might also want to check out:
Wooden Boat Magazine: http://www.woodenboat.com/
Boat Design Net: http://www.boatdesign.net/
USCG “NVIC 7-95" - Inspection
, Repair and Maintenance
of Wooden Hulls:
Wood Handbook, FPL-GTR-113 (WOOD As An Engineering Material, published by the Forest Service
Laboratories at the University of Wisconsin)